The conference, organized by USA gay, bi and trans workplace equality experts Out and Equal brought together some of the world’s leaders in diversity.

Bingham used her speech to highlight how much had changed since she entered work in the City of London in the 80s.

She said: ‘It was a very hedonistic decade. Greed was good. And society had evolved to have a very permissive attitude to things like sex before marriage. But there were very few LGBT role models and certainly none in the workplace.

‘In 1986 I went to the final concert of Wham and in 1986 George Michael was straight. It’s hard to believe.’

But at that point she was still straight. She only started to come out when a sympathetic Ernst & Young partner questioned her about her ‘flatmate’ who was really her girlfriend.

But despite their being support for LGBT employees in the company, it was not universal.

Bingham said: ‘There was still no LGBT role models in the workplace and few in society so I stayed safely and firmly in the closet.

‘During this time [early 1990s] it was reported to me that one of the senior guys in my firm had been holding court in the pub and had said, to anyone prepared to listen, that “the only thing wrong with Liz Bingham is she needs a good seeing to”. He was a complete moose.’

Since the, she said, an enormous amount has changed. But she urged people not to stop working to improve, telling the audience: ‘At Ernst & Young we do regular people surveys and ask a series of questions designed to measure the level of engagement our people have with the organization.

‘We have seen a direct correlation between highly engaged people in our business and delivering the best. This is not a nice thing to do, it is absolutely essential.’

Speaking afterwards to Gay Star News, Bingham told us how Ernst & Young tried to apply their LGBT work globally.

‘There is a real visibility right from the top of the firm from the global executive and our global chairman,’ she said. ‘What we try do is translate this at a local area level into, for example, helping in-country teams to set up LGBT networks.

‘But it’s small steps, it’s incremental.’

She also said the size of the challenge of improving LGBT rights worldwide was enormous.

‘I am an optimist by nature. But I was at the European Commission a month ago at a conference for the African, Caribbean and Pacific countries and you just look at that and wonder how on earth we are going to make any progress at all.

‘You are faced with deeply held religious and societal views on LGBT issues. It could be another generation or two until those countries wake up to the importance of true diversity for everybody.

‘So we’ve just got to keep on pressing and I think it’s really important that we don’t declare victory in the mature countries and think our job is done. We’ve got to keep pushing and keep the energy going in other areas.’